Thumbnail Image

Size frequency – equations used to estimate standard lengths and estimate







Also available in:
No results found.

Related items

Showing items related by metadata.

  • Thumbnail Image
    Document
    size frequency - equations 2013
    Also available in:
    No results found.

    The available data on the sizes of neritics tus caught by the different fisheries are presented as: Available size frequency data: The size frequency data available in the IOTC databases is presented in FL_NERITIC.csv (27-05-2013). All size data strata not recorded as fork length was converted into fork length by using the equations in Equations.pdf. Fish recorded under size classes other than those used for neritic tu species was assigned to the corresponding size class/es for each species (fir st class is 10cm for all neritic tus and class interval is 1cm). Details about the amount of data available to create the above files can be found in SF_reference.xls
  • Thumbnail Image
    Meeting
    Report of the Eleventh Session of the IOTC Working Party on Billfish 2013
    Also available in:
    No results found.

    The Eleventh Session of the Indian Ocean Tu Commission?s (IOTC) Working Party on Billfish (WPB) was held in La Réunion, France, from 18 to 22 September 2013. A total of 24 (23 in 2012) participants attended the Session, including one invited expert, Dr. Humber Andrade, from the Universidade Federal Rural de Permbuco, Brazil. The meeting was opened on 18 September, 2013 by the Chair, Dr Jérôme Bourjea (La Réunion, France), who welcomed participants to La Réunion, France. Catch, Catch-and-effort, Size data The WPB RECOMMENDED that all CPCs assess and improve the status of catch-and-effort data for marlins (by species) and sailfish, noting that improvements to the data for the EU fleets and its provision to the IOTC Secretariat, would be most beneficial to the work of the WPB. (para. 25) Effect of piracy on billfish fisheries The WPB NOTED that, although no specific alysis of the impacts of piracy on fisheries in the Indian Ocean were presented at this meeting, paper IOTC–2013–WPB11–07 Re v_1 indicated that there has been a substantial displacement of catch (Fig. 1) and effort eastward (Fig. 2). Since 2004, annual catches have declined steadily, largely due to the continued decline in the number of active Taiwan,Chi longliners in the Indian Ocean (Fig. 3). In recent years, the proportion of fishing effort of the Japanese longline fleet sharply decreased in the north-western Indian Ocean (off the Somalia coastline), while fishing effort increased in the area south of 25°S, especia lly off western Australia. (para. 40) The WPB NOTED that the relative number of active longline vessels in the IOTC area of competence have declined substantially since 2008 (Fig. 3), and AGREED that this was likely due to the impact of piracy activities in the western Indian Ocean. Since 2011, there has been an increase in the relative number of active longline vessels in the Indian Ocean for Japan (68 in 2011 to 98 in 2012), Chi (10 in 2011 to 32 in 2012) and the Philippines (2 in 2011 to 14 i n 2012) (Fig. 3). (Para. 41) Pakistan gillnet fishery RECALLING IOTC Resolution 12/12 to prohibit the use of large-scale driftnets on the high seas in the IOTC area, paragraph 1, which states: “1. The use of large-scale driftnets on the high seas within the IOTC area of competence shall be prohibited.” “Large-scale driftnets” are defined as gillnets or other nets or a combition of nets that are more than 2.5 kilometers in length whose purpose is to enmesh, entrap, or entangle fish by drifting on the surface of, or in, the water column.”, the WPB RECOMMENDED that the SC note the findings of the study that gillnets in excess of the 2.5 km limit are being used by the gillnet fleets of Pakistan on the high seas, in contravention of Resolution 12/12. (para. 44) Revision of the WPB workplan The WPB RECOMMENDED that the SC consider and endorse the workplan and assessment schedule for the WPB for 2014, and tentatively for future years, as provided at Appendix XII and Appendix XIII, respectivel y. (para 192) Consolidated recommendations of the Eleventh Session of the Working Party on Billfish The WPB RECOMMENDED that the Scientific Committee consider the consolidated set of recommendations arising from WPB11, provided at Appendix XIV, as well as the magement advice provided in the draft resource stock status summary for each of the billfish species under the IOTC mandate: (para 205) o Black marlin (Makaira indica) – Appendix VII o Blue marlin (Makaira nigricans) – Appendix VIII o Strip ed marlin (Tetrapturus audax) – Appendix IX o Indo-Pacific sailfish (Istiophorus platypterus) – Appendix X o Swordfish (Xiphias gladius) – Appendix XI ???????????????????A summary of the stock status for billfish species under the IOTC mandate is provided in Table 1.
  • Thumbnail Image
    Meeting
    Fishery in Iran with particular reference to billfish 2013
    Also available in:
    No results found.

    Fishery for tu and tu-like species is a major component in large pelagic fisheries in Iran and one of the most important activities in the Persian Gulf and Oman Sea. There are 4 coastal provinces in that areas about 6500 out of 12000 vessels consist of fishing boat, dhows and vessel which are engaged in tu and tu-like species fishing activities in the coastal and offshore waters. Gillnet and purse seine are two main fishing gear for catching large pelagic species in the IOTC area competency and also some of small boats used trolling in coastal fisheries. The annual production of large pelagic in Iran was 236,000 t in 2012 and 208,000 t belongs to tu and tu-like fishes in the Indian Ocean areas. Those catch consist of Yellowfin tu35110 t, Skipjack 27051 t, Big eye tu 1644 t, Longtail tu 76297 t, Kawakawa26249 t, Frigate tu 8219 t, Billfish11297 t, Indo-pacific king mackerel 5537 t, Narrow- barred Spanish mackerel16510 t. Although billfish are not normally targeted species, they are very common in offshore gillnet catches and are considered as by-catch species. Total billfish production in Iran in 2012 was 11315t and this is around 5.4% of the total tu and tu like fish production. The Sailfish domited the billfish catch with 6365 t, followed by marlins 4364 t, and Swordfish 586 t. Iran has taken various actions to implement the Scientific Committee and WPB10 recommendations. One of actions taken by Iran is improving data collection system for billfish fishery during 2012 .It is noteworthy to say that for 2012 we could identify and include swordfish and marlines catch in our data base. we have implemented artisal gillnets modification of logbook template to meet mandatory minimum statistic requirement, particularly with regards to data recording of vessel position in IOTC area for target species, By-catch and discard.

Users also downloaded

Showing related downloaded files

No results found.